More long-range Spitfires and daylight Bomber Command raids, with added nationalistic abuse (was: #1 Jet of World War II)

Guy Alcala wrote:
Mike Marron wrote:
"Gord Beaman" ) wrote:

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

Also see: F-8 Crusader

Why?

An example of an a/c that was able to vary its wing's angle of
incidence in flight.

Correct.

This was presumably intended to be read as followup to his other
message, where he postulates that Al Minyard was referring to AoI
rather than AoA, but that assumes you're familiar with the F-8.

Incorrect. As you said above Guy, it was just an example of an A/C
that was able to vary its wing's angle of incidence in flight.

I have a slightly different reading of Al's intent, but we can let Al tell
us what he meant.

Like I've said, I generally tend to give people of the doubt instead
of automatically assuming they're wrong so I can come back with
some gratuitous, knee-jerk, argumentative retort like Gord does.
In other words, even my ab intitio, pre-solo student pilots know
that angle of attack is created by the tailplane providing a force
(positive or negative) in the direction of the lift of the wings.
Depending on whether the wing lift is foward or aft of the CG, the
elevator will have to produce positive or negative lift to rotate the
A/C about its lateral axis. Basic stuff, hence my willingness to
give Al the benefit of the doubt and assume he meant angle of
incidence rather than angle of attack. I could be wrongly
misinterpreting Al, but I'll sit back now and let Al tell us what he
meant.

-Mike Marron
CFII, A&P, UFI (fixed-wing, weightshift land & sea)

On Wed, 10 Sep 2003 07:53:32 +0100, Dave Eadsforth
wrote:


Agree with all of the above analysis - and thanks for the useful summary
of aspect ratios; both the B-24 and the B-29 must have glided well...

To enlarge on my 'thick wing section' description, and working from
memory of a book read long ago (which can be fatal), I recall that Davis
conceived of a wing section that was based on a mathematically deformed
circle, which he believed would give a more laminar flow. The thicker,
'teardrop-shaped' aerofoil section that resulted was also very useful
structurally, given that he wanted to combine it with a high aspect
ratio wing.

Of course, any wing section inboard of the engines was going to have its
airflow messed up considerably by a few minor essentials; like engine
nacelles and de-icing boots etc etc, but the wing outboard of the
engines may have performed as Davis believed it should during cruise.

True that the high aspect ratio conferred most of the advantages of L/D
ratio, but perhaps Davis's ideas on the wing section itself should not
be forgotten.

Cheers,

Dave

Thanks. I knew that Davis had designed a laminar flow section, but was
unaware that the section had increased thickness. Interesting stuff.

Al Minyard

Mike Marron wrote:
Also see: F-8 Crusader

Gord Beaman wrote:
Why?

Guy Alcala wrote:
An example of an a/c that was able to vary its wing's angle of
incidence in flight. This was presumably intended to be read as
followup to his other message, where he postulates that Al Minyard
was referring to AoI rather than AoA, but that assumes you're
familiar with the F-8. I have a slightly different reading of Al's
intent, but we can let Al tell us what he meant.

Al Minyard wrote:
Yep, I meant AoI, but my source called it AoA, so I slavishly copied
it that way.

Common error, but I knew you meant AoI not AoA.

Al Minyard:
I agree that the F-8 was somewhat unique in its ability
to vary the AoI.

Not true. Thousands (perhaps tens of thousands) of "variable
incidence" A/C (e.g: flexwing, weightshift A/C known as "trikes")
have been manufactured and are in widespread use throughout
the world as cropdusters, towplanes, aerial observation and
photography platforms, trainers, recreational and military special
forces A/C. I happen to have logged almost 2,000 hrs. in these
magical variable incidence machines myself.

Of course, trikes aren't the only variable incidence A/C, Jack
Northrop's revolutionary flying wing designs such as the XB-35
strategic bomber and XP-56 and XP-74 fighter planes were
also variable incidence. Of course, then there's the B-2 Stealth
bomber.

Unlike a conventional 3-axis A/C, the angle of incidence and
angle of attack in all of these A/C are the same during flight.
The primary difference between my own personal "variable
incidence" A/C and the B-2 with regards to stability is that
the B-2 incorporates a computerized gust load alleviation
system (GLAS) to counteract air turbulence forces whereas
I use my chest and biceps to counteract turbulence! Either
way, watching a tailless, flying wing land is pure poetry in motion
and flying one is pure sex.

Al Minyard:
Of course, with the fuselage horizontal pitch at 0, AoI equals
AoA :-)

Exactly right.

-Mike Marron

Dave Eadsforth wrote:

snip

To enlarge on my 'thick wing section' description, and working from
memory of a book read long ago (which can be fatal), I recall that Davis
conceived of a wing section that was based on a mathematically deformed
circle, which he believed would give a more laminar flow. The thicker,
'teardrop-shaped' aerofoil section that resulted was also very useful
structurally, given that he wanted to combine it with a high aspect
ratio wing.

Of course, any wing section inboard of the engines was going to have its
airflow messed up considerably by a few minor essentials; like engine
nacelles and de-icing boots etc etc, but the wing outboard of the
engines may have performed as Davis believed it should during cruise.

snip

He was quite irritated that Consolidated didn't provide full covers for the main
gear wheel wells, as he felt that defeated much of the drag reduction.

Guy

Mike Marron wrote:

Al Minyard:
Of course, with the fuselage horizontal pitch at 0, AoI equals
AoA :-)

Exactly right.

-Mike Marron



Ok, I see now why you said "see the F-8 Crusader".
John emailed me this URL which partially explains it's wing
shenanigans.
http://pacificcoastairmuseum.org/200...Crusader/j.asp

Quote from URL:
"No, the wing isn't about to fall off. It was designed to do
this so that the fast moving Crusader could slow down enough to
land on the carriers. This also kept the nose of the airplane
down during landing so the pilot could see."
Unquote

I still don't see the purpose here unless it's _only_ advantage
is the second sentence in the quote there. Why would an increase
in AOA 'help the a/c slow down for a carrier landing'?...of
course it would 'slow down' BUT it'd now be way high on the
glidepath TOO. Just as it would be if you hauled back on the
stick...the _only_ advantage that I can see for this capability
of the F-8 is to lower the nose for better visibility from the
cockpit. Mind you, that must have been a large advantage imo.
'cause it seems to me that that'd be a big engineering project.

Please guys, tell me where I'm wrong here...

A/c is flying smoothly down a three degree glide-path,
the wing's AoA is 5 degrees. AoI is zero. (guesses of course)

Pilot pops the 'AoI switch', AoI becomes 5 degrees, AoA becomes
10 degrees, a/c tries to climb, pilot prevents that by pushing
stick forward, AoA now returns to 5 degrees and a/c ~returns to
glidepath. (Fuselage is now at a steeper angle than it was).

I'll tell you what will help, explain where I'm wrong in calm
terms or ignore this post. Insults about my lineage, my skin
colour, my mental capacity etc will only make you look bad to the
lurkers and won't affect me one whit. (I'm old and tough
skinned).



--

-Gord.

In article , Gord Beaman
?@?.? writes
I still don't see the purpose here unless it's _only_ advantage
is the second sentence in the quote there. Why would an increase
in AOA 'help the a/c slow down for a carrier landing'?...of
course it would 'slow down' BUT it'd now be way high on the
glidepath TOO. Just as it would be if you hauled back on the
stick...the _only_ advantage that I can see for this capability
of the F-8 is to lower the nose for better visibility from the
cockpit. Mind you, that must have been a large advantage imo.
'cause it seems to me that that'd be a big engineering project.

Concorde went with physically lowering the nose (out of the pilot's
view) and cranking the AoA right up.

--
John

" wrote:

Mike Marron wrote:

Al Minyard:
Of course, with the fuselage horizontal pitch at 0, AoI equals
AoA :-)

Exactly right.

-Mike Marron



Ok, I see now why you said "see the F-8 Crusader".
John emailed me this URL which partially explains it's wing
shenanigans.
http://pacificcoastairmuseum.org/200...Crusader/j.asp

Quote from URL:
"No, the wing isn't about to fall off. It was designed to do
this so that the fast moving Crusader could slow down enough to
land on the carriers. This also kept the nose of the airplane
down during landing so the pilot could see."
Unquote

I still don't see the purpose here unless it's _only_ advantage
is the second sentence in the quote there. Why would an increase
in AOA 'help the a/c slow down for a carrier landing'?...of
course it would 'slow down' BUT it'd now be way high on the
glidepath TOO. Just as it would be if you hauled back on the
stick...the _only_ advantage that I can see for this capability
of the F-8 is to lower the nose for better visibility from the
cockpit. Mind you, that must have been a large advantage imo.
'cause it seems to me that that'd be a big engineering project.

Please guys, tell me where I'm wrong here...

The other advantage of keeping the fuselage more level is that it provides
more ground clearance at the tail, so you can increase the AoA (and fly
slower) while still maintaining pilot view and sufficient tail clearance.

Guy

"Gord Beaman" ) wrote:

Ok, I see now why you said "see the F-8 Crusader".
John emailed me this URL which partially explains it's wing
shenanigans.
http://pacificcoastairmuseum.org/200...Crusader/j.asp

Quote from URL:
"No, the wing isn't about to fall off. It was designed to do
this so that the fast moving Crusader could slow down enough to
land on the carriers. This also kept the nose of the airplane
down during landing so the pilot could see."
Unquote

I still don't see the purpose here unless it's _only_ advantage
is the second sentence in the quote there. Why would an increase
in AOA 'help the a/c slow down for a carrier landing'?...of
course it would 'slow down' BUT it'd now be way high on the
glidepath TOO. Just as it would be if you hauled back on the
stick...

Haven't you heard the old axiom, "pitch for airspeed, power
for altitude?" (See below).

the _only_ advantage that I can see for this capability
of the F-8 is to lower the nose for better visibility from the
cockpit. Mind you, that must have been a large advantage imo.
'cause it seems to me that that'd be a big engineering project.

The F-8 won the Collier Trophy for the year's (mid 1950's) greatest
achievement in aviation. Besides just increasing the visibility, the
variable incidence wing also enabled the sleek and very fast
fighter to maintain the slower speeds required for carrier ops.

Please guys, tell me where I'm wrong here...

A/c is flying smoothly down a three degree glide-path,
the wing's AoA is 5 degrees. AoI is zero. (guesses of course)

Pilot pops the 'AoI switch', AoI becomes 5 degrees, AoA becomes
10 degrees, a/c tries to climb, pilot prevents that by pushing
stick forward, AoA now returns to 5 degrees and a/c ~returns to
glidepath. (Fuselage is now at a steeper angle than it was).

You're not just along for the ride so before you start flipping
switches and reconfiguring the A/C for the approach and
landing you anticipate changes in airspeed, drag, power and
stick pressure etc. so as to stay on the glideslope w/o exceeding
your critical angle of attack.

In other words, in your scenario above when the pilot increases
the wing angle of incidence (7-deg's), he simultaneously adjusts
his pitch and throttle settings as needed so as to remain stabilized
on the glideslope. He just doesn't gaily "pop the AoI switch" and
then react to what the airplane does...he thinks ahead and anticipates
what the airplane will do and plans accordingly (e.g: "fly the
plane" and pitch for airspeed power for altitude" etc.).

Maybe an F-8 driver can jump in here and explain better than I can.
I can only tell you that when landing my variable incidence A/C,
I can adjust the wing's angle of incidence (instantly if I wish)
simply by pushing the control bar full forward (unlike a conventional
airplane, the stick is situated horizontally so it's called a "bar"),
or pulling the bar full aft into my gut. And I can coordinate the wing
angle of incidence/attack and throttle depending on the type
of landing (e.g: short field, soft-field, crosswind, solo or 2-up, wet
or dry wing, etc.) fully stabilized on the glideslope w/o porpoising
up and down and/or making any radical changes in airspeed...


-Mike ( could land 3 times [crowhop] on an aircraft carrier Marron

Mike Marron wrote:


In other words, in your scenario above when the pilot increases
the wing angle of incidence (7-deg's), he simultaneously adjusts
his pitch and throttle settings as needed so as to remain stabilized
on the glideslope. He just doesn't gaily "pop the AoI switch" and
then react to what the airplane does...he thinks ahead and anticipates
what the airplane will do and plans accordingly (e.g: "fly the
plane" and pitch for airspeed power for altitude" etc.).


Of course Mike, I understand that but I just broke it down so
that it's easier for me to describe.

I still don't see what this AoI control will do _other_ than
give the pilot better downward visibility for landing and less
drag for high speed operation. Is there some other aspect that
I'm not seeing?...or is that it in a nutshell?...

It doesn't help to compare conventional a/c with ultra-lights
because I don't understand them very well.


--

-Gord.

Guy Alcala wrote:


The other advantage of keeping the fuselage more level is that it provides
more ground clearance at the tail, so you can increase the AoA (and fly
slower) while still maintaining pilot view and sufficient tail clearance.

Guy

Yes...that makes sense, perhaps they designed the a/c for very
high speed flight by having the AoI very low to reduce drag but
needed to increase the Aoi for landing to, as you say, allow
'eventless' landings...
--

-Gord.